[Hyper-V] replication between two servers over 10Gbit slow


Dec 29, 2019
i have got 2 the same Dell R710 servers. Both have got Server 2016 with Hyper-V role installed. And both are in a domain.

I would like to use HyperV VM replication between those machines.

I am using a direct 10Gbit SPF connection between them. When i use iperf it shows me an average of about 4.5Gbit. Does anybody have an idea why it is not reaching 10Gbit? I am using 2 Mellanox Connectx-3 cards.

When i try to use replication between my 2 Dell r710 servers i am not even reaching 1 Gbit.

I have tried disabling QoS, SRV-IO, RSS on the 2 hosts. But doesnt have much impact.

Any ideas on how to increase this replication throughput?

I am using Windows Server 2016. My storage on both sides is a RAID10 4x1,92TB Micron Enterprise SSDs array. Crystal Disk Mark shows me that the storage on both sides is faster than the 10Gbit is able to handle so storage isn't the bottleneck in my opinion.
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